1. Field of the Invention
The present invention relates to drive circuits for servomotors and more specifically to a drive circuit in which the drive power is automatically inhibited when the servosystem is driven to its mechanical limits.
2. Description of the Prior Art
Servosystems are frequently designed to operate between specified limits of mechanical movement. Motion beyond these limits is restrained by mechanical stops. When the moving element in such systems reaches a limiting position, the servomotor is stalled and the drive current increases to a level that would destroy the motor. In order to protect the motor under such circumstances, microswitches are often employed in the limiting mechanism to terminate the power flow to the servomotor until the motor is commanded to reverse its direction of rotation.
The present invention provides means to reduce the cost and to increase the reliability of such systems by eliminating the need for the microswitches and their attendant wiring.